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 * modification, are permitted provided that the following conditions are
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 *
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 * in the documentation and/or other materials provided with the
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#ifndef SVGListPropertyTearOffHelper_h
#define SVGListPropertyTearOffHelper_h

#include "core/svg/properties/SVGPropertyTearOff.h"
#include "wtf/TypeTraits.h"

namespace blink {

template <typename ItemProperty>
class ListItemPropertyTraits {
  STATIC_ONLY(ListItemPropertyTraits);

 public:
  typedef ItemProperty ItemPropertyType;
  typedef typename ItemPropertyType::TearOffType ItemTearOffType;

  static ItemPropertyType* getValueForInsertionFromTearOff(
      ItemTearOffType* newItem,
      SVGElement* contextElement,
      const QualifiedName& attributeName) {
    // |newItem| is immutable, OR
    // |newItem| belongs to a SVGElement, but it does not belong to an animated
    // list, e.g. "textElement.x.baseVal.appendItem(rectElement.width.baseVal)"
    // Spec: If newItem is already in a list, then a new object is created with
    // the same values as newItem and this item is inserted into the list.
    // Otherwise, newItem itself is inserted into the list.
    if (newItem->isImmutable() || newItem->target()->ownerList() ||
        newItem->contextElement()) {
      // We have to copy the incoming |newItem|,
      // Otherwise we'll end up having two tearoffs that operate on the same
      // SVGProperty. Consider the example below: SVGRectElements
      // SVGAnimatedLength 'width' property baseVal points to the same tear off
      // object that's inserted into SVGTextElements SVGAnimatedLengthList 'x'.
      // textElement.x.baseVal.getItem(0).value += 150 would mutate the
      // rectElement width _and_ the textElement x list. That's obviously wrong,
      // take care of that.
      return newItem->target()->clone();
    }

    newItem->attachToSVGElementAttribute(contextElement, attributeName);
    return newItem->target();
  }

  static ItemTearOffType* createTearOff(ItemPropertyType* value,
                                        SVGElement* contextElement,
                                        PropertyIsAnimValType propertyIsAnimVal,
                                        const QualifiedName& attributeName) {
    return ItemTearOffType::create(value, contextElement, propertyIsAnimVal,
                                   attributeName);
  }
};

template <typename Derived, typename ListProperty>
class SVGListPropertyTearOffHelper : public SVGPropertyTearOff<ListProperty> {
 public:
  typedef ListProperty ListPropertyType;
  typedef typename ListPropertyType::ItemPropertyType ItemPropertyType;
  typedef typename ItemPropertyType::TearOffType ItemTearOffType;
  typedef ListItemPropertyTraits<ItemPropertyType> ItemTraits;

  // SVG*List DOM interface:

  // WebIDL requires "unsigned long" type instead of size_t.
  unsigned long length() { return toDerived()->target()->length(); }

  void clear(ExceptionState& exceptionState) {
    if (toDerived()->isImmutable()) {
      SVGPropertyTearOffBase::throwReadOnly(exceptionState);
      return;
    }
    toDerived()->target()->clear();
  }

  ItemTearOffType* initialize(ItemTearOffType* item,
                              ExceptionState& exceptionState) {
    if (toDerived()->isImmutable()) {
      SVGPropertyTearOffBase::throwReadOnly(exceptionState);
      return nullptr;
    }
    DCHECK(item);
    ItemPropertyType* value = toDerived()->target()->initialize(
        getValueForInsertionFromTearOff(item));
    toDerived()->commitChange();
    return createItemTearOff(value);
  }

  ItemTearOffType* getItem(unsigned long index,
                           ExceptionState& exceptionState) {
    ItemPropertyType* value =
        toDerived()->target()->getItem(index, exceptionState);
    return createItemTearOff(value);
  }

  ItemTearOffType* insertItemBefore(ItemTearOffType* item,
                                    unsigned long index,
                                    ExceptionState& exceptionState) {
    if (toDerived()->isImmutable()) {
      SVGPropertyTearOffBase::throwReadOnly(exceptionState);
      return nullptr;
    }
    DCHECK(item);
    ItemPropertyType* value = toDerived()->target()->insertItemBefore(
        getValueForInsertionFromTearOff(item), index);
    toDerived()->commitChange();
    return createItemTearOff(value);
  }

  ItemTearOffType* replaceItem(ItemTearOffType* item,
                               unsigned long index,
                               ExceptionState& exceptionState) {
    if (toDerived()->isImmutable()) {
      SVGPropertyTearOffBase::throwReadOnly(exceptionState);
      return nullptr;
    }
    DCHECK(item);
    ItemPropertyType* value = toDerived()->target()->replaceItem(
        getValueForInsertionFromTearOff(item), index, exceptionState);
    toDerived()->commitChange();
    return createItemTearOff(value);
  }

  bool anonymousIndexedSetter(unsigned index,
                              ItemTearOffType* item,
                              ExceptionState& exceptionState) {
    replaceItem(item, index, exceptionState);
    return true;
  }

  ItemTearOffType* removeItem(unsigned long index,
                              ExceptionState& exceptionState) {
    if (toDerived()->isImmutable()) {
      SVGPropertyTearOffBase::throwReadOnly(exceptionState);
      return nullptr;
    }
    ItemPropertyType* value =
        toDerived()->target()->removeItem(index, exceptionState);
    toDerived()->commitChange();
    return createItemTearOff(value);
  }

  ItemTearOffType* appendItem(ItemTearOffType* item,
                              ExceptionState& exceptionState) {
    if (toDerived()->isImmutable()) {
      SVGPropertyTearOffBase::throwReadOnly(exceptionState);
      return nullptr;
    }
    DCHECK(item);
    ItemPropertyType* value = toDerived()->target()->appendItem(
        getValueForInsertionFromTearOff(item));
    toDerived()->commitChange();
    return createItemTearOff(value);
  }

 protected:
  SVGListPropertyTearOffHelper(
      ListPropertyType* target,
      SVGElement* contextElement,
      PropertyIsAnimValType propertyIsAnimVal,
      const QualifiedName& attributeName = QualifiedName::null())
      : SVGPropertyTearOff<ListPropertyType>(target,
                                             contextElement,
                                             propertyIsAnimVal,
                                             attributeName) {}

  ItemPropertyType* getValueForInsertionFromTearOff(ItemTearOffType* newItem) {
    return ItemTraits::getValueForInsertionFromTearOff(
        newItem, toDerived()->contextElement(), toDerived()->attributeName());
  }

  ItemTearOffType* createItemTearOff(ItemPropertyType* value) {
    if (!value)
      return nullptr;

    if (value->ownerList() == toDerived()->target())
      return ItemTraits::createTearOff(value, toDerived()->contextElement(),
                                       toDerived()->propertyIsAnimVal(),
                                       toDerived()->attributeName());

    return ItemTraits::createTearOff(value, 0, PropertyIsNotAnimVal,
                                     QualifiedName::null());
  }

 private:
  Derived* toDerived() { return static_cast<Derived*>(this); }
};

}  // namespace blink

#endif  // SVGListPropertyTearOffHelper_h